Automated haematology analysers: a four-way comparison

Four automated haematology analysers--the Coulter S + IV, Coulter STKS, Sysmex NE8000, and Technicon H1--were evaluated for operational and quantitative differences. The measured blood count parameters (red cell, white cell and platelet counts, mean cell volume [MCV], haematocrit and haemoglobin) all compared well with the S + IV, although the MCV showed the greatest variation. Of the white cell differential parameters, neutrophils, lymphocytes and eosinophils correlated well with manually performed 400 cell differential counts. Mononuclear cell and monocyte counts generated by the S + IV and NE8000 (respectively) compared poorly with the manual method. The STKS, NE8000 and H1 gave an acceptable five cell population differential from samples stored in K2EDTA for up to 18 h, although the monocyte count from the NE8000 showed considerable variation during that period. All instruments were shown to operate efficiently in either primary or secondary operating mode, but the STKS and NE8000 were considerably faster than the H1, and easier to use in the automated mode.